<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id="app">
        <button @click="buy(5)">可乐5元</button>
        <button @click="buy(10)">咖啡10元</button>
        <button @click="buy(8)">牛奶8元</button>
        <p>余额：{{money}}</p>
    </div>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.7.16/dist/vue.js"></script>
    <script>
        const app=new Vue({
            el:"#app",
            data:{
                money:100,

            },
            methods: {
                buy(price){
                    this.money-=price
                }
                
            }         
        })

    </script>

</body>
</html>